Set after the series ends, Revenge of the Energy Vampire
(alternate link) was written by Bookworm Gal and goes a bit Darker and Edgier than the cartoon while retaining everyone's characterization and showing what Nos-4-A2 is capable of doing on-screen rather than just hinting at it like in the show.
Revenge of the Energy Vampire provides examples of:
- Air-Vent Passageway: Savy uses the ventilation shafts to sneak around Star Command. She's a skinny kid, so that helps.
- Back from the Dead: Nos-4-A2. A Brain Pod found his microprocessor and rebuilt him, hoping to use him against Zurg. Nos-4-A2 just left as soon as repairs were done.
- Berserk Button: Nos-4-A2 does not like having his plans ruined or losing. At all.
- Big Brother Instinct: XL goes into utter panic when XR goes missing and nearly has a breakdown when viewing the tape of Nos-4-A2 torturing his brother. Buzz, Mira and Booster aren't in much better shape.
- Bizarre Alien Senses: Nos-4-A2 can sense energy.
- Cold-Blooded Torture: What Nos-4-A2 does once he kidnaps XR.
- Continuity Nod: A few important ones from the cartoon show up.
- Nos-4-A2 mentally goes through all his past defeats and who is to blame.
- XL's new position at Star Command after his Heel–Face Turn at the end of "Revenge of the Monsters."
- Nos-4-A2 repeats the graphic threat he described to XR during "The Slayer." This time, however, he gets to go through with it.
- Ty Parsec's stint as a wirewolf is mentioned several times.
- XL's past relationship with the Fixer.
- Did You Think I Can't Feel?: XR isn't fond of the notion that all of the times his body has been destroyed are harmless since they hurt.
- Electric Torture: Nos-4-A2 uses a charger unit to recharge XR, using high voltage while providing very few joules so it would hurt more than provide power. He combined it with the Vampiric Draining to keep XR online and suffering as long as possible.
- Electronic Speech Impediment: When Team Lightyear manage to find XR, he's suffered enough damage to his systems that his voice stammers and is filled with static.
- Emotion Bomb: One of the energy vampire's powers allows him to do this to robots.
- Extended Disarming: One of the first things that Nos-4-A2 does is remove anything XR might have that he could use against him somehow. Due to his Do-Anything Robot status, it takes a little while.
- Face Palm: Nebula does this when too many people eavesdropped on a private meeting.
- Forced to Watch: Nos-4-A2 tries to invoke this by sending a recording to Star Command. He later sends them a live broadcast, showing his handiwork. It backfires. Spectacularly.
- Good Cop/Bad Cop: When confronting the Fixer, Ty Parsec fills the role of good cop while Savvy and XL share the role of bad cop.
- Good Is Not Soft: Celeste is a mother figure to those who work for her. This means she'll do things like bring a sick staff member soup and a blanket, offer a sympathetic ear to a heartbroken co-worker whose boyfriend cheated on her (and help destroy said boyfriend's belongings and put the fear of Celeste in that guy) and hack into Star Command's data banks for XL's birthday and his old body. And she's been mentioned to have pretty good aim with a weapon. She might do paperwork, but she's still a Space Ranger.
- Ty is perfectly willing to kill Nos-4-A2 for what he's done to XR.
- Heroic Sacrifice: When XR blurts out Nos's location, it's with the full knowledge that he won't survive. Mercifully averted when Buzz and Mira find him in time.
- Hidden Depths: XL. While he might not have been the most clever of criminals, he still understands their mindset enough to deduce that Nos might have an accomplice helping him hide the bodies.
- Hoist by His Own Petard: When Nos-4-A2 sends a live broadcast to Star Command to show his handiwork, XR uses to opportunity to reveal where he's being held. Nos does not take it well.
- Hypocritical Heartwarming: Downplayed since it's technically being referred to in the past tense but while trying to take down Nos-4-A2, XL yells "Hold still so I can blast you into scrap metal. No one hurts my little brother except me. And I don't do that anymore."
- Loophole Abuse: When Lana begins tracking down his old body to help find XR, XL points out that this would be violating his probation. However, Lana just explains that there's a rule that says that it's okay so long as he has permission from his superior (ostensibly to help with any attacks on Star Command). And since Lana is his direct superior...
- My Sister Is Off-Limits: XL once took XR aside and told him very firmly that he was not to even flirt with Lana.
- Obfuscating Stupidity: XR pretends to have his will broken long enough to get an opening.
- Ominous Opera Cape: Nos-4-A2 wears one, which even the Fixer notes is a bit strange for a robot.
- Papa Wolf: Commander Nebula. This is his response to the aforementioned recording."I don't care how you do it. I don't care what it takes. XR will be found and Nos-4-A2 will pay for his actions."
- Pinned to the Wall: Well, XR gets pinned to an exam table. With bolts drilled through his arms and legs.
- Pragmatic Villainy: The main reason that Tradeworld is pro-robo equality is less to do with any actual morality and more so that said robots are able to engage in commerce/be liable for taxes.
- Red Eyes, Take Warning: Nos-4-A2. The Fixer even notes that most people prefer robots without red eyes.
- Reminiscing About Your Victims: Nos-4-A2 does this a bit, mentioning a robot he kept alive for two days with the method he's using on XR.
- The Renfield: The Fixer vaguely takes on this role, agreeing to some minor favors in exchange for the off-lined robots Nos-4-A2 hunts.
- The Guardbots that Nos-4-A2 bite so they would provide him with information from Star Command.
- Sadist: Nos-4-A2 enjoys the pain of others, which bites him in the butt.
- Something Only She Can Do: When the rescue party shows up for XR, he's completely blind and mostly deaf due to his torture and as such, reacts to his friends like Nos-4-A2, further endangering his life. Finally Mira manages to get through to him by using her ghosting powers, a sensation he recognizes and immediately realizes could only be from her, which calms him down enough for them to get him stable enough to move; interestingly this was completely unintentional on her part since she was just trying to get him loose from the table he was pinned to as she believed that would calm him down a bit but ended up calming him down completely.
- Spanner in the Works: During one of his hunts, Nos-4-A2 get knocked into a dumpster and brings back a flyer stuck to his cape. This flyer is for a restaurant found only on Tradeworld, which XR sees,and later uses to screw over Nos-4-A2 one last time.
- Terms of Endangerment: Just like in the show, Nos-4-A2 tends to refer to XR as "Little One."
- Vampire Bites Suck: Being drained by the energy vampire is unpleasant, to say the least.
- Vampiric Draining: Nos-4-A2 does this to XR. Repeatedly.
- Villain Protagonist: Nos-4-A2 is the character who gets the most focus in the story and the title character. He is also the one who is hunting other robots and torturing XR.
- Villainous Breakdown: After XR ruins his fun Nos-4-A2 take his rage out on the poor robot ranger, ripping out parts before crushing his motor.
- What Measure Is a Non-Human?: Mentioned both in the Author's Notes and in the story itself. Rather than a single unified set of laws throughout the Galactic Alliance, different planets have different rights concerning robots and whether they're treated as citizens. Surprisingly Tradeworld is one of the planets where a sentient robot has equal rights as anyone else.
- The X of Y: Revenge of the Energy Vampire
- Younger Than They Look: XR, who by this point is only two years old. Lampshaded after Mira show suprise at this (and the realization that the day she first met him was his second day alive), XR notes that it's not like robots have childhoods.
